Ames Laboratory and Critical Materials Institute researchers have developed a two stage extraction process to selectively separate neodymium and dysprosium from spent NdFeB magnets.

Description

Many of the technologies important to reducing green-house gas emissions involve the use of permanent magnets, specifically NdFeB magnets. Found in automotive motors, consumer electronics and in wind turbine generators, these high-energy permanent magnets play an important in our everyday lives. Despite their widespread use and the incorporation of rare earth elements in the magnets, it is estimated that perhaps as little as one percent of rare earth metals are recycled from spent and waste magnets.

One of the factors that impact recycling is the harsh conditions that are typically involved in the recycling process. ISURF #04150 and #04391 use pyrometallurgical techniques to selectively extract the rare earth elements from NdFeB magnets, leaving the iron and boron residue behind. The first extraction step uses liquid magnesium to selectively remove neodymium from the magnet, while the second step utilizes liquid bismuth to remove the dysprosium. The rare earth elements are readily recovered from the extractant using rotary evaporation.